<?php

/**
 * Interface to be implemented by Observers. Observers are part of the observer
 * pattern. They observe observables and receive notifications about changes of
 * observables.
 * 
 * @package be.appcraft.util
 * @version $Revision: 1.1 $
 *
 * @author Stijn Van Bael
 * @since 1.0
 */
interface Pageley_Util_Observer {
	/**
	 * Notifies this observer about a change of an observable.
	 *
	 * @param Observable $observable: the observable that has changed
	 * @param object $data: additional data related to the update
	 */
	public function notify($observable, $data = null); 
}